Sound quality evaluation of fan noise based on advanced hearing-related parameters

Sound quality evaluation of fan noise is a challenge due to its spectral and temporal structures. Tonal components and modulated sounds are often the cause of customer complaints. Thus, besides frequency-weighted level like dB(A) or loudness, other parameters are required. Some years ago, a “Hearing Model” was developed with the intention of explaining and describing psychoacoustic effects. Applying the Hearing Model to sound quality tasks allows evaluating the spectral and temporal patterns of a sound (“Relative Approach” analysis) where absolute level or loudness is often without significance. The Relative Approach analysis emphasizes all relevant signal components concerning human auditory perception: tonal and transient signals.